ISO 5209:2019

Overview

ISO 5209:2019 - General purpose industrial valves - Marking - sets out mandatory and optional marking requirements for metal industrial valves (plastic valves are excluded). The standard defines where and how markings must be applied (integral cast/forged/stamped/laser-marked or on a marking plate/identification plate), material and fixing expectations for plates, and how this marking regime works together with valve product or performance standards. It ensures consistent valve identification, traceability and safe installation across process industries.

Key topics and technical requirements

• Mandatory vs supplementary markings: Items such as nominal size, PN/Class designation, material and manufacturer’s name/trademark are mandatory (see Clause 4.2). Other items (e.g., maximum allowable temperature, PS, trim, flow coefficient, year of manufacture) are supplementary or optional unless required by a product/performance standard.
• Marking methods and locations: Markings must be integral (cast/forged/stamped/laser-marked) or on a marking plate; painted-on markings are not permitted. Markings may be placed on the body, bonnet/cover, flange, marking plate or identification plate.
• Plate requirements: Marking and identification plates must be resistant to atmospheric corrosion and suitable for the valve’s allowable temperature.
• Special cases and omissions: Small valves (DN ≤ 50, or threaded ≤ 2") may omit or relocate some mandatory markings when impracticable. For Class valves the word “CLASS” may be abbreviated to “CL” if space is limited. For PN valves “DN” may be omitted if followed immediately by the PN value.
• Detailed marking items: The standard details items such as flow direction arrow, threaded end identification, ring joint number, maximum allowable pressure (PS), melt identification, service symbols, quality/test markings, inspector ID, allowable differential pressure (Δp) and closing direction (see Clause 5 and Table 1).

Applications and who uses it

ISO 5209:2019 is intended for:

• Valve manufacturers - to apply compliant, durable markings for product identification and compliance.
• Procurement/specifiers and OEMs - to specify marking requirements in purchase orders and tender documents.
• Inspectors, testing and certification bodies - to verify traceability and conformity during inspection and testing.
• Plant engineers and maintenance teams - to ensure correct installation, safety, and replacement by reading durable, standardized markings.
• Process industries - oil & gas, petrochemical, power, water, and general industrial plants where clear valve identification is critical for safety and maintenance.

Keywords: ISO 5209:2019, valve marking, industrial valves marking, valve identification, marking plate, PN Class, nominal size, flow direction arrow, valve traceability.

Related standards

• ISO 7-1 (pipe threads, pressure-tight)
• ISO 228-1 (pipe threads, non-pressure-tight)
• ANSI/ASME B1.20.1 (pipe threads, general purpose)
• Relevant valve product or performance standards (take precedence where requirements differ)